pdfjs-dist/lib/core/metadata_parser.js

/**
 * @licstart The following is the entire license notice for the
 * Javascript code in this page
 *
 * Copyright 2021 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * @licend The above is the entire license notice for the
 * Javascript code in this page
 */
"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.MetadataParser = void 0;

var _xml_parser = require("./xml_parser.js");

class MetadataParser {
  constructor(data) {
    data = this._repair(data);
    const parser = new _xml_parser.SimpleXMLParser({
      lowerCaseName: true
    });
    const xmlDocument = parser.parseFromString(data);
    this._metadataMap = new Map();
    this._data = data;

    if (xmlDocument) {
      this._parse(xmlDocument);
    }
  }

  _repair(data) {
    return data.replace(/^[^<]+/, "").replace(/>\\376\\377([^<]+)/g, function (all, codes) {
      const bytes = codes.replace(/\\([0-3])([0-7])([0-7])/g, function (code, d1, d2, d3) {
        return String.fromCharCode(d1 * 64 + d2 * 8 + d3 * 1);
      }).replace(/&(amp|apos|gt|lt|quot);/g, function (str, name) {
        switch (name) {
          case "amp":
            return "&";

          case "apos":
            return "'";

          case "gt":
            return ">";

          case "lt":
            return "<";

          case "quot":
            return '"';
        }

        throw new Error(`_repair: ${name} isn't defined.`);
      });
      const charBuf = [];

      for (let i = 0, ii = bytes.length; i < ii; i += 2) {
        const code = bytes.charCodeAt(i) * 256 + bytes.charCodeAt(i + 1);

        if (code >= 32 && code < 127 && code !== 60 && code !== 62 && code !== 38) {
          charBuf.push(String.fromCharCode(code));
        } else {
          charBuf.push("&#x" + (0x10000 + code).toString(16).substring(1) + ";");
        }
      }

      return ">" + charBuf.join("");
    });
  }

  _getSequence(entry) {
    const name = entry.nodeName;

    if (name !== "rdf:bag" && name !== "rdf:seq" && name !== "rdf:alt") {
      return null;
    }

    return entry.childNodes.filter(node => node.nodeName === "rdf:li");
  }

  _parseArray(entry) {
    if (!entry.hasChildNodes()) {
      return;
    }

    const [seqNode] = entry.childNodes;
    const sequence = this._getSequence(seqNode) || [];

    this._metadataMap.set(entry.nodeName, sequence.map(node => node.textContent.trim()));
  }

  _parse(xmlDocument) {
    let rdf = xmlDocument.documentElement;

    if (rdf.nodeName !== "rdf:rdf") {
      rdf = rdf.firstChild;

      while (rdf && rdf.nodeName !== "rdf:rdf") {
        rdf = rdf.nextSibling;
      }
    }

    if (!rdf || rdf.nodeName !== "rdf:rdf" || !rdf.hasChildNodes()) {
      return;
    }

    for (const desc of rdf.childNodes) {
      if (desc.nodeName !== "rdf:description") {
        continue;
      }

      for (const entry of desc.childNodes) {
        const name = entry.nodeName;

        switch (name) {
          case "#text":
            continue;

          case "dc:creator":
          case "dc:subject":
            this._parseArray(entry);

            continue;
        }

        this._metadataMap.set(name, entry.textContent.trim());
      }
    }
  }

  get serializable() {
    return {
      parsedData: this._metadataMap,
      rawData: this._data
    };
  }

}

exports.MetadataParser = MetadataParser;